Connector for electrical distribution systems



Nov. 7, 1961 F. J. SOMES, JR 3,007,996

CONNECTOR FOR ELECTRICAL DISTRIBUTION SYSTEMS Original Filed March 5,1957 5 Sheets-Sheet 1 H 77'0/M Ys Nov. 7, 1961 F. J. SOMES, JR 3,007,996

CONNECTOR FOR ELECTRICAL DISTRIBUTION SYSTEMS Original Filed March 5,1957 5 Sheets-Sheet 2 50' 7 INVENTOR.

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Nov. 7, 1961 F. J. SOMES, JR 3,007,996

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Nov. 7, 1961 F. J. SOMES, JR 3,007,996

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United States Patent O 3,007,996 CONNECTOR FOR ELECTRICAL DISTRIBUTIONSYSTEMS Frederick J. Somes, Jr., Detroit, Mich., assignor to GeneralElectric Company, a corporation of New York Original application Mar. 5,1957, Ser. No. 643,977, now Patent No. 2,931,097, dated Apr. 5, 1960.Divided and this application Oct. 2, 1957, Ser. No. 687,755

2 Claims. (Cl. 174-40) This invention relates to electrical powerdistribution systems and apparatus for installing the same. Moreparticularly, the invention relates to improved apparatus for supportingan electrical power distribution system during and after theinstallation thereof, and improved methods and apparatus for installingelectrical power distribution systems which are particularly adapted forlarge scale installations such as industrial plants. This application isa division of the applicants co-pending application Serial No. 643,977,filed March 5, 1957 now Patent Number 2,931,097.

An object of the invention is to provide improved apparatus forsupporting the components of an electrical power distribution systemduring and after the installation thereof.

Another object of the invention is to provide an improved electricalpower distribution system incorporating novel means which reduces to aminimum the time, labor and expense required to install and maintain thesystem.

It is a further object to provide an improved power distribution systemof this character, and method for installing the same, which willminimize or eliminate undesired deflection of the parts both during andafter installation, thus facilitating the assembly operation andresulting in a sturdy installation capable of withstanding heavy use.

It is also an object to provide, in one form of the invention, animproved installation mechanism for electrical distribution systemswhich is of extremely inexpensive construction and may be fabricatedusing standard materials and with a minimum of machining expenses.

It is another object to provide an improved installation mechanism forelectrical distribution systems which includes novel means forreleasably guiding one portion of the installation mechanism and whichreduces to a minimum the effort required to move the system parts intoinstalled position.

The above as well as other objects and advantages of the presentinvention will become apparent from the following description, theappended claims, and the accompanying drawings, wherein:

FIGURE 1 is a top plan view of electrical power distribution apparatusembodying the present invention, showing the same installed in anelectrical power distribution system;

FIGURE 2 is an enlarged side elevational view of a portion of thestructure illustrated in FIGURE 1;

FIGURE 3 is a perspective view of apparatus embodying the presentinvention, showing the same during an installation with the guide blockabout to enter the supporting rollers;

FIGURE 4 is an end view of the guide block and at tached cable;

FIGURE 5 is a longitudinal sectional view of the structure illustratedin FIGURE 4, taken on the line 5-5 thereof and showing the manner ofattaching the cable to the guide block;

FIGURE 6 is a top plan view of apparatus embodying the presentinvention, showing the guide block entering between the rollers FIGURE 7is an end elevational view of the structure illustrated in FIGURE 6 withportions sectioned for ice clarity, showing the positionof thereleasable guide and the anti-friction bearing for a roller;

FIGURE 8 is a side elevational view of the structure illustrated inFIGURE 6;

FIGURE 9 is a transverse sectional view of a portion of the structureillustrated in FIGURE 2, taken on the line 9-9 thereof, showing thecable guide in released position;

FIGURE 10 is a transverse sectional view of a portion of the structureillustrated in FIGURE 2, taken on the line 10-10 thereof and showing theconstruction of the trolley duct;

FIGURE 11 is a sectional elevational view of the structure illustratedin FIGURE 10, taken on the line 11-11 thereof and showing the ductconnector;

FIGURE 12 is a perspective view of another embodiment of the guideblock;

FIGURE 13 is a longitudinal sectional view of the structure illustratedin FIGURE 12, taken on the line 13-13 thereof;

FIGURE 14 is a longitudinal sectional view of the duct connector usedbetween the first two duct sections; and

FIGURE 15 is a transverse sectional view of a portion of the structureillustrated in FIGURE 14, taken on the line 15-15 thereof.

In general, the improved method of installing the electrical powerdistribution apparatus includes the steps of electrically andmechanically joining two initially separate sections of a trolley ductin end-to-end relationship to form an elongated unitary structure, thesections being joined at a particular location, such as at one end of aproposedbusway; moving the joined sections a predetermined distancealong a predetermined path;'suspending the joined sections atpredetermined spaced intervals; restraining the suspending means againstmovement in a direction substantially parallel to the direction of theproposed busway; and thereafter successively electrically andmechanically joining additional sections in end-toend relationship withrespect to the previously joined sections, moving the joined sections apredetermined additional distance after each new section is added, andsuspending the joined sections at additional spaced intervals until allof the desired sections have been electrically and mechanicallyconnected and moved to the desired location.

The apparatus of the present invention incorporates improved means whichfacilitate the rapid installation of a relatively large electrical powerdistribution system with a minimum of equipment, labor and expense. Theapparatus also incorporates improved means which materially increasesthe etficiency of the workmen installing the system, thereby increasingthe work output rate of the workmen and reducing the cost of the system.

Referring to the drawings, and more panticulanly to FIGURE 1 thereof, anelectrical power distribution system, generally designated 20, isillustrated which is comprised of a plurality of spaced, substantiallyparallel rows 22, 24, 26, 28 and 30 of trolley ducts 32 which areadapted to supply electrical power to lighting fiXltllI'CS 34 or otherdesired electrical equipment. In the illustrated embodiment of theinvention, fixtures 34 are shown in FIGURE 2 as being suspended bychains 35 which are secured to trolley ducts 32 by hooks 37, thefixtures being electrically connected to trolley ducts 32 by conduits 39and conventional plugs or trolleys 41. While multiple trolley ducts 32are illustrated, it will be understood that the present invention may beutilized in the installation of only one trolley duct, if desired. Eachof the rows of trolley ducts may, for example, extend for severalhundred feet, the electrical power distribution system 20 illustratedbeing particularly adapted for factories or other relatively largebuildings.

In the embodiment of the invention illustrated, each of the trolleyducts 32 includes a plurality of sections, such as 36 and 38 shown inFIGURE 11, which are elec' trically and mechanically joined together inend-to-end relationship to form a unitary structure. The individualsections may be of any desired or conventional length; for example, eachsection may be approximately ten feet in length.

As shown in FIGURES 9 and 10, each section of trolley duct 32 includes ahousing generally indicated at 40 having spaced side walls 42 and 44joined by a top wall 46. The lower end portions of the side Walls, asviewed in FIGURES 9 and 10, are provided with inwardly extending flanges48 and 50, the inner edges 52 and 54 of which terminate in spacedsubstantially parallel relationship to define an elongated slot 56.Flanges 48 and 50 serve as tracks which extend along housing 40 and uponwhich conventional trolleys, plugs or other connectors such as conduits39 of FIGURE 2 are mounted in 'a conventional manner.

Housing 40 encloses electrical conductors 58 and 60 disposed in spacedrelationship with respect to walls 42, 44 and 46 of the housing. Theconductors are also disposed in inwardly spaced relationship withrespect to the flanges 48 and 50*, electrical insulators 62 beingprovided at spaced intervals to support conductors 58 and 60 andelectrically insulate the conductors from the housing. At a positionadjacent top wall 46, the side walls are provided with generallyV-sectioned longitudinally extending inclined sections which formgrooves 68 and 70 extending longitudinally of the housing 40 for theentire length thereof. These grooves are adapted to engage thesupporting assemblies as will be described below in greater detail.

In order to support the ducts, a plurality of spaced supportingassemblies generally indicated at 72 in FIGURE 9 and having verticallyextending suspension rods 74 are provided, the upper end portions ofthese rods being fixed to the roof trusses or other appropriatesupporting structures of the building. Any desired or conventionalmeans, such as clamps, may be employed to fix the upper end portions ofthe rods to the roof trusses. The lower end portions of the rods arethreaded, as at 76 in FIGURE 7, for the reception of nuts 78 and 80. Aplurality of brackets 82 are provided, each having a pair of dependinglegs or side portions 84 and 86 integrally joined by a web portion 88,the free ends of the side portions 84 and 86 being provided withoutwardly projecting flanges 90 and 92. The lower end portion of eachrod 74 projects through an aperture 94 in the web portion of theassociated bracket and the web portion is retained on the stringer bynuts 78 and 80. Although fixed with respect to rod 74, the nuts are nottightened against the web portion with the result that the bracket ispermitted to rotate about the longitudinal axis of the associated rod.This will permit the bracket and its associated parts to adjustthemselves to the entering duct, as described later.

In order to maintain the positions of suspension rods 74 when the ducthousing is being installed, a plurality of tension wires 96 extendbetween adjacent rods, as seen best in FIGURE 2. These wires are securedto the rods at the lower ends thereof, and'the first and last wires in arow will be secured to adjacent portions 97 of the stationary structure.Any tendency of rods 74 to sway in the direction of movement of the ductbars as they are being installed will be resisted by the combined effectof wires 96, thus facilitating the installation process.

For the purpose of supporting the duct housing, a pair of spaced rollers98 and 100 are suspended from each bracket 82. 1 In particular, rollers98 and 100' are rotatably mounted on vertical stub shafts 102 and 104respectively as seen in FIGURE 7, these shafits having reduced andthreaded upper ends 106 and 108 projecting through bracket flanges 90and 92 and secured to these flanges by nuts 110. A channel-shaped crossmember 112 is secured between the shouldered portions of shafts 102 and104 and flanges and 92. Anti-friction bearings 114 are provided at thelower ends of shafts 102 and 104 for rotatably supporting rollers 98 and100. The supporting elements are each provided with beveled surfacesadapted to project into the longitudinally extending grooves 68 and 70provided on the duct housing, thus providing a firm support whichprevents transverse rocking of the housing but permits it to glidelongitudinally.

A releasable guide 116 is provided between each pair of rollers whichserves to guide a cable, as will be described hereinafter in greaterdetail. The guide includes a spring 118, best seen in FIGURES 7, 8 and9, the coiled central portion of which is secured to the underside ofcrosspiece 112 by a rivet and washer 120. The end portions of the springproject forwardly of the crosspiece and one end portion 122 is bentdownwardly and transversely while the other end portion 124 is bentdownwardly and rearwardly so that the transversely projecting section ofportion 122 rests on the rearwardly projecting section of portion 124when the guide member is in the closed position. In order to releasablyretain spring 118 in the above-described closed position, a clamp 126 isprovided, one end of which is pivoted to portion 122 of the spring. Aflange 128 is provided on the outer end of the clamp, the flangeprojecting downwardly and bearing against portion 124 of the spring soas to restrain this portion against lateral movement. Clamp 126 is alsoprovided with a downwardly projecting tab 130 which is adapted to beengaged by a cam so as to release the spring, thereby permitting thecable to drop from guide 116, as will be described below in greaterdetail. It will be noted that each bracket 82, together with itsassociated parts including rollers 98 and 100, and guide 116,constitutes a supporting assembly, designated generally at 72, for theduct housing.

For the purpose of mechanically joining individual sections of trolleyduct 32 in end-to-end relationship, a plurality of connectors 132 areprovided which overlap adjacent sections of the trolley duct, as seen inFIGURES 10 and 11. Each of the connectors includes an inner element 134and an outer elmeent 136, both of these elements being of channel-shapedcross section. The distance between the outer surfaces of the flanges ofinner element 134 is less than the distance between the inner surfacesof the flanges of outer element 136 and, as shown in FIGURES 10 and 11,the flanges are adapted to engage the lower ends of the side walls 4-2and 44 of the housing 40 at a position adjacent the junction of theseside walls with the flanges 48 and 50 respectively. A plurality ofscrews 138 are provided which extend through the web portions ofelements 136 and threadably engage the web portions of elements 134.With such a construction, when the screws are tightened, flanges 48 and50 of the housing are clamped between the flanges of inner element 134and the web of outer element 136. The length of connectors 132 issufficient to provide a firm frictional grip on housings 40 which willhold adjacent housings in endto-end relation.

In the assembly of the sections of the trolley duct, one end portion ofa connector 1132 is secured to one end portion of a housing 40 in themanner previously described, after which the adjacent housing section isslidably inserted in the other end portion of the connecting member sothat the flanges 48 and 50 of the second housing are disposed betweenthe inner and the outer elements of the connector in the mannerpreviously described. The screws are then tightened so as to securelyclamp the adjacent sections of the trolley duct in end-to-endrelationship.

Any desired means may be provided for electrically connecting conductors58 and 60 of the adjacent sections of the trolley duct. For example,conventional pins 140 may be utilized, the pins being inserted in theend portions of conductors 58 and 60 in the conventional manner, asshown in FIGURE 11.

To facilitate the installation of the trolley ducts, a con- .nector 142is also provided which is adapted to rfi'echztni cally join the firstand second sections of the trolley duet in end-to-end relationship. Itwill be noted that since the first section of the duct will at times beunsupported, its" connection with the second section will be subject toa bending stress. Connector 142 includes an inner element 144 and anouter element 146 similar in construction to the corresponding elementsof connectors 132, as seen in FIGURE 14. However, in order to compensatefor defiection of the first and second sections of the trolley ductduring the installation thereof, the leading end portion of connector142 is bent upwardly relative to the trailing end thereof. With such aconstruction, the tendency of the leading section to sag whenunsupported by rollers 98 and 100 will be counteracted by the originalupward inclination given it by connector 142, as seen in FIGURE 14, andthe entire assembly will therefore retain a substantially alignedcondition. Connector 142 will be mounted in a manner similar to thatdescribed with respect to connecto-r 132.

A guide block 148 is provided which is adapted to be secured to the freeend of the leading section of the trolley duct to facilitate theinstallation thereof. The guide block includes a body portion having anextension 150 projectiny outwardly and rearwardly from the lower edgethereof, as seen in FIGURE 5, and a head portion 152 which is joined toand narrower than the body. Between the head portion and the bodyportion, a pair of guideways 154 are provided. Each of the guidewaysincludes a converging section 156 at the forward end and a substantiallystraight section, the straight sections being of substantially the sameconfiguration as grooves 68 and 70 in housing 40. An upwardly open slot160 is also provided in the head portion of the guide block, the slotsloping upwardly and rearwardly and communicating with a diagonallydownwardly extending aperture 162 defined by the body portion, as seenin FIGURE 5. Aperture 162 is adapted to receive a cable 164 and aplurality of set screws 166 are provided to releasably secure the cableto the guide block, so that the guide block and the attached trolleyduct may be pulled through the agency of the cable and the cabledisassembled from the guide block when a trolley duct has been com--pleted. A cam 167 having an upwardly and rearwardly sloping surface isfixed to the top of guide block 148 for engagement with tab 130 of guideclamp 126, so that guide 116 may be automatically released as describedbelow.

In securing guide block 148 to the free end of the leading section of atrolley duct 32, extension 150 of the guide block is insertedintermediate the side walls 42 and 44 of the housing, as seen in FIGURESand 6, so that the bottom wall of the extension engages the innersurfaces of the flange portions 48 and 50 of the housing. Flanges 48 and50 are clamped between extension 150 of the guide block and a retainingplate 168 having a serrated surface which engages the outer surfaces ofthe flange portions 48 and 50 of the housing. Screws 170 are providedwhich extend through retaining element 168 and threadably engageextension 150 of the guide block to clamp the guide block to the trolleyduct. When the guide block is mounted on the trolley duct, guideways 154on the guide block are aligned with grooves 68 and 70 of the trolleyduct, the upper surfaces of the guideways being substantially coplanarwith grooves 68 and 70 in constituting a continuation thereof.

In the installation of the electrical power system, supportingassemblies 72 are suspended from a roof truss or other suitablestationary supporting structure at spaced intervals and in alignedrelationship along the proposed rows of trolley ducts, the supportingassemblies being suspended from the roof truss, for example, bysuspension rods 74 in such manner that they are free to rotate about therod axes. Guides 116 are placed in their closed position so that the endportions of spring 118 are disposed in; the previously describedrelation and retained by clamp 126. Cable 164 is then passed throughguides 116 in one row as shown in FIGURES 6, 7 and 8 as well as inFIGURE 3, after which the free end of the cable is inserted in aperture162 of guide block 148 and secured to the guide block by set screws 166.The cable extends along the proposed location of the trolley duct and awinch (not shown) or other suitable means is provided at the free end ofthe cable.

Guide block 148 is secured to the leading end of the first section ofthe trolley duct in the manner previously described, after which thetrailing end of the first section is mechanically and electricallyconnected to the second section in end-to-end relationship through theagency of connector 142 and pins 140. Succeeding sections of the ductare joined through pins 140 and connectors 132. The individual sectionsof trolley duct are preferably joined at one location, such as at oneend of each proposed row of duct, thereby obviating the necessity of theworkman moving from such location during the assembly of the duct.

After the first and second sections have been secured together inend-to-end relationship, such sections are pulled toward the nearestsupporting assembly 72 by cable 164. As the guide block approaches thefirst supporting assembly, guide 116 on the first support member tendsto raise the guide block toward rollers 98 and 100 and, at the sametime, connector 142 tends to compensate for the deflection of theunsupported first section of the trolley duct. It will be appreciatedthat with an elongated section of trolley duct, the end being pulled bythe cable will tend to sag downwardly away from the supporting assembly,and guide 116 as well as connector 142 will serve to guide the guideblock toward the rollers.

Converging portions 156 of grooves 154 initially engage rollers 98 and100. As the guide block moves through the rollers, grooves 154 on theguide block will align grooves 68 and 70 of the housing with therollers, and the latter will thus glidably support the initially joinedsections of the trolley duct. During this movement, cam 167 will engagetab lifting clamp 126 and permitting the end portions of guide spring118 to spread apart so that the end of cable 164 which is fastened toguide block 148 may pass through. The position of cam 167 issuch thatwhen cable 164 is released rollers 98 and 100 will be supporting guideblock 148. The pivotal connection between bracket 82 and suspension rod74 will permit the rollers to adjust themselves to receive the guideblock, and tension wires 96 will prevent any tendency of rods 74 to swayin the direction of movement of the duct housing.

The remaining sections of the trolley duct are then successivelyelectrically and mechanically joined to the previously joined sections,the mechanical connections being effected through the agency ofconnectors 132, and the joined sections are pulled by the cable throughthe supporting assemblies. The guide block thus effects the initialengagement with the rollers of each supporting assembly and serves toalign the duct grooves with the rollers.

After all the sections of a trolley duct have been joined together andpulled into engagement with the supporting assemblies, the cable andguide block may be removed and reused. Conductors 58 and 60 may, ofcourse, be electrically connected to a suitable source of potential inany desired manner. Light fixtures 34 or other electrical equipment maybe installed during the assembly of the trolley duct or may be installedafter the trolley duct is in its final position.

FIGURES l2 and 13 illustrate a modified form of the glide block which issimilar in principle to that previously described but incorporates novelfeatures which greatly reduce its cost of manufacture. The modifiedguide block, generally indicated at 172, comprises a shelllike bodyportion 174 of sheet metal having a pair of side walls connected by anupper Web 176. An upwardly extending earn structure 177, correspondingin function to cam 167 of the previous embodiment, is secured to web176. Outwardly facing longitudinal grooves 178 of V-shaped cross sectionare formed in body 174 between the side walls and upper web, thesegrooves being adapted to conform to the periphery of the rollerspreviously described. The lower portions of the body side walls are bentinwardly, as shown in FIGURE 12, with a pair of inwardly extendingflanges 180. A pair of clamping plates 132 and 184 are disposed onopposite sides of flanges 180 at the rearward portion of guide block172, these brackets being adapted to secure the guide block to a ducthousing section in a manner similar to that described with respect toextension 150' and gripping plate 168 of the previous embodiment. Inparticular, gripping teeth 186 are provided on the downwardly extendingflanges of plate 182 so that the flanges of the duct housing as well asflanges 180 of guide block 172 may be simultaneously gripped betweenplates 182 and 184.

The guide block shown in FIGURES 12 and 13 is also provided with meansfor securing a cable 188, this means including a bracket 190 having apair of upwardly and inwardly extending flanges 192 and 194 engaging thefront and rear edges of housing web 176. Bracket 190 is disposed beneaththe housing web and is provided with a clamping nut 196 threadablymounted therein, this nut being engageable with a gripping plate 198disposed between bracket 190 and the underside of web 176. A clearanceslot 200 is formed in forward flange 192 of bracket 190 for thereception of cable 188, and a pair of apertures 202 and 204 are formedin web 176 so that the cable may be threaded through these apertures.When cable 188 is in the position shown in FIG URE 13, screw 196 may betightened to clamp the cable firmly between gripping plate 198 and theunderside of web 176, the disposition of the cable within apertures 202and 204 further adding to the gripping effect of the device.

In order to provide guide means to facilitate entry of the rollers intogrooves 178, guide block 172 is provided with a pair of wire loops 206and 208 so formed as to present a pair of converging paths within whichthe rollers will be guided so as to enter grooves 178. Wire 206 islooped as shown in FIGURE 12 with its rearwardly extending legs securedbetween the upper portions of grooves 178 and web 176. The forward legportions of wire 206 extend upwardly, forwardly and then downwardly asshown in FIGURES 12 and 13, with the downwardly directed leg sectionsbeing closer together than the remainder of the legs. Wire 203 islikewise of looped form with its rearwardly extending legs secured tohousing 174 below grooves 178, and this wire extends forwardly anddownwardly as seen in FIGURE 13. Central portion 210 of wire 206 issecured to a pair of crosspieces 2.12 extending between the legs of wire208, as best seen in FIGURE 12, for strengthening purposes.

The looped central portion 214 of wire 203 carries a tongue plate 216 tofurther aid the guiding function of block 172. It will be seen that withthis constructional arrangement, which is relatively inexpensive tofabricate, wires 206 and 208, together with tongue plate 216, will forma pair of converging paths which will guide the block between rollers 93and 100, previously described,

E5 until these rollers come into engagement with grooves 178.

While it will be apparent that the preferred embodiments of theinvention disclosed are well calculated to fulfill the objects abovestated, it will be appreciated that the invention is susceptible tomodification, variation and change Without departing from the properscope or fair meaning of the subjoined claims.

What is claimed is:

1. In an electrical distribution system of the type in which a pluralityof elongated duct sections are drawn successively into engagement with aplurality of spaced aligned supporting assemblies, first and second ductsections for said system, said sections each comprising an upper web, apair of downwardly extending legs, and a pair of bottom flanges, aconnector for fastening together said first and second sections, saidconnector comprising upper and lower elements engageable with oppositesides of the flanges on said first and second sections, those portionsof said elements engageable with said first section being bent upwardlyfrom the remainder of said elements, and means for holding said elementsin tight engagement with said flanges, whereby said connector will tendto hold said first duct section in an upwardly tilted position withrespect to said second duct section.

2. Electric power distribution apparatus comprising a plurality ofelongated duct sections each comprising a generally tubular housing anda plurality of electrical conductors supported in insulated relationtherein, means electrically and mechanically connecting said ductsections in end-to-end substantially straight-line relation, a pluralityof roller supporting means engaging said duct sections at longitudinallyspaced points and suspending said sections in elevated condition, eachof said supports comprising at least one roller engaging a portion ofsaid housings, said supporting means supporting said sections forrolling movement in a direction parallel to their length, a leading ductsection, initial connecting means connecting said leading duct sectionin endwise relation to said connected plurality of duct sections, saidinitial connecting means comprising at least one splicing plate havingportions overlapping adjacent end portions of said leading duct sectionand an adjacent one of said connected duct sections, the portion of saidsplice plate overlapping said leading duct section being bent upwardlyrelative to the remaining portion of said splice plate, and means forrigidly attaching said splice plate to each of the duct sectionsconnected thereby to rigidly connect said leading duct section inupwardly tilted relation to said plurality of connected duct sections,whereby to facilitate engagement of the leading end of said leadingsection with each of said roller supporting means as said sections aremoved longitudinaly in the direction of said leading section.

References Cited in the file of this patent UNITED STATES PATENTS1,504,954 Kamp Aug. 12, 1924 2,462,721 Cohen Feb. 22, 1949 2,626,301Hammerly Jan. 20, 1953 2,840,400 DAzzo June 24-, 1958 FOREIGN PATENTS725,305 Great Britain Mar. 2, 1955

